body{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

#wrapBg{
    width: 343px;
    height: 480px;
    background-image: url(../img/bg.jpg);
    position: relative;
    overflow: hidden;
}

#headTitle{
    background-image: url(../img/head.jpg);
    background-repeat: no-repeat;
    width: 263px;
    height: 77px;
    position: absolute;
    left: 53px;
    top: 100px;
}

#headBird{
    float: right;
    margin-top: 25px;
}

#startBtn{
    width: 85px;
    height: 29px;
    background-image: url(../img/start.jpg);
    position: absolute;
    left: 50%;
    top: 250px;
    /* margin-left: -43px; */
    transform: translateX(-50%);
}

#grassLand1{
    width: 343px;
    height: 14px;
    background-image: url(../img/banner.jpg);
    position: absolute;
    left: 0;
    top: 423px;
}

#grassLand2{
    width: 343px;
    height: 14px;
    background-image: url(../img/banner.jpg);
    position: absolute;
    left: 343px;
    top: 423px;
}